take a potshot at

take a potshot at someone or something

 
1. Lit. to shoot at someone or something, as with a shotgun. (A potshot refers to the type of shooting done to provide meat for the cooking pot.) The hunters were taking potshots at each other in the woods. Someone has been taking potshots at my mailbox!
2. Fig. to criticize or censure someone or something, often just to be mean. Why are you taking potshots at me? What did I do to you? Everyone in the audience was taking potshots at the comedian's toupee.
See also: potshot, take